package collection;

import java.util.ArrayList;
import java.util.Collection;

//集合中保存的是元素的地址
public class CollectionDemo3 {
    public static void main(String[] args) {
        Collection c=new ArrayList();
        Point p=new Point(1,2);
        c.add(p);
        System.out.println(p);//(1,2)
        System.out.println(c);//[(1,2)]

        p.setX(100);//把p里的x做标改/设置为100
        System.out.println(p);//(100,2)
        System.out.println(c);//[(100,2)]
    }
}
